Yeah any type of grease will work, but heres my disclaimer.. Im not sure if it will affect your water chemistry.
We use vaseline at my commerical pool because its cheap, and hasnt affected water chemistry for me personally. However, yes it does slowly dissappear and the valve tends to stick again over time. although This usually isnt a problem for us because my dummy lifeguards tend to blow gaskets all the time, thus we just reapply the jelly. Ive found that having some type of grease on top of the gasket and inside the port, helps maintain the gaskets longer, and its easier to turn the handle.
The clicking noise you hear is normal. There is a large spring just under the handle that applies pressure to the lid to make sure the valve stays closed. The vaseline helps eliminate that clicking and sticking which is the sound of friction from the valve as it rotates around the top of the gasket inside.
esim13: So your only seeing large amounts of water through the viewfinder, while backwashing?
Because this is normal. Your supposed to see alot of water rushing past, that backwash pipe leads to your sewer or waste based on your setup. When you backwash your filter, you are reversing the direction of water flow through your filter. Normally while on "filter" or "rinse", the water enters the top pipe into your filter, runs through the sand, or DE, and the clean water returns to your pool through the lower pipe.
On "backwash", your mulitport reverses the direction of water> water from your pool now enters the filter from the bottom pipe, and is forced up through the sand, (this pushes all the garbage that has been caught be the sediment upwards to the top of the filter. This dirty water then exists your filter through the top pipe, where the multiport directs the flow to your backwash pipe (through your viewfinder) and into the sewer or waste hose, so that the garbage does not re-enter your pool.
So basically when your mulitport is set to "backwash" you should see alot of water running through this glass viewfinder. This water should look dirty at first, (if your filter is dirty) and will gradually clear up to let you know that the filter is clean again.